JP2005242710A - Infrared sensor and infrared monitoring system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an infrared sensor and an infrared monitoring system using it causing no synchronous deviation even when an infrared ray from the infrared sensor in the infrared monitoring system is interrupted for a long time. <P>SOLUTION: This infrared sensor used for the infrared monitoring system, in which infrared pulses are sequentially transmitted to the infrared sensor for detecting interruption of the infrared pulses, is provided with a reference time processing part 1 generating a reference time generated from a standard time acquired by a radio signal, a light transmitting/receiving timing processing part 2 computing light transmitting/receiving timing of an infrared ray from the reference time, and a light transmission/reception control part 3 controlling light transmission/reception of the infrared pulse based on the light transmission timing and the light receiving timing. The light transmission/reception control part 3 is provided with a light receiver 18 receiving the infrared pulse, a light receipt processing part 14 performing alarm processing and signal processing based on the light reception timing of the received infrared pulse, a light transmission processing part 11 generating a detection signal based on the light transmission timing of the data from the light reception processing part 14 and performing signal processing, and a light transmitter 17 transmitting the infrared pulses from the light transmission processing part 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an opposed infrared sensor for detecting an intruder into a large-scale facility site by shielding infrared rays and an infrared monitoring system using the same.

  Various infrared monitoring systems that use infrared rays to detect intruders entering the site have been proposed. For example, Patent Document 1 includes a light transmitter having a plurality of light transmitting units that emit infrared rays toward a warning area, and a light receiver having a light receiving unit corresponding to the light transmission part, which is installed across the warning area. Thus, there is described an infrared warning device that issues a warning by detecting the shielding of infrared rays from the light transmitting unit to which the light receiving unit corresponds.

  In addition, as an infrared warning device, it is composed of a plurality of sensor groups and a controller unit, and the controller unit receives detection information detected by the sensor unit by a wireless signal, and outputs an alarm generation output when judged to be abnormal. Wireless sensor systems that output control signals are also known.

  FIG. 3 is a schematic diagram showing an example of a sensor configuration used in the infrared monitoring system. In FIG. 3, the master sensor No. that transmits and receives infrared pulse signals within the premises is shown. 1 and a plurality of slave sensors No. 1 2-No. 5 are arranged wirelessly at intervals. Each sensor includes a battery, an infrared pulse light transmitter 17, a light receiver 18, and a control panel 19 for controlling the sensor, and a plurality of light transmitters 17 and light receivers 18 are arranged. The infrared pulse is sequentially transmitted through each sensor, and the master sensor No. 1 → Slave sensor no. 2-5 → Master sensor no. The flow of 1 and the reverse flow are combined.

  In order to detect an intruder, an infrared pulse periodically output from the light transmitter 17 in the sensor does not reach the light receiver 18 of the opposite sensor (slave sensor No. 2 → slave sensor No. 2 in FIG. 2). 3 and slave sensor No. 3 in the reverse direction → slave sensor No. 2) are detected by shading, and the shading signal which is the shading information is sequentially transmitted through each sensor and the information is input from the master to the control panel. . The control panel processes the input sensor information with a sequencer or the like, and outputs control data for controlling the operation of devices such as alarm display and buzzer according to the processing result.

  FIG. 4 is a time chart showing a transmission state of a signal superimposed on an infrared pulse in beam 2 or beam 4 of the conventional infrared monitoring system in the sensor configuration of FIG. In FIG. 4, A and B are infrared pulses on which signals such as a top pulse indicating the start of an infrared pulse, sensor control data from the control panel, and sensor address data in an alarm section are superimposed, and infrared pulses A and B are constant. The light is transmitted at a period of. D is the slave sensor No. 2 → Slave sensor no. 3 is an infrared pulse (2) including a light-shielding signal in which the light-shielding is detected, and DB is an error infrared pulse (4).

  Infrared pulses A and B are transmitted from the master sensor to the next slave sensor, the infrared pulses are sequentially transferred by each sensor, returned to the master sensor, and input to the control panel.

  When each sensor receives an infrared pulse from the next stage sensor, it internally processes the infrared pulse, and in order to match the signal timing of the previous stage sensor, it is controlled by an internal clock to send an infrared pulse signal after a lapse of a certain time from the received light. . In FIG. 2 and slave sensor no. 3, the second and third periods of the infrared pulse A and the second period of the infrared pulse B are completely shielded from light, and recovered in the middle (3) of the third period of the infrared palace B.

  Slave sensor No. Infrared pulse signals A and B from the light transmitter 2 indicate that the slave sensor no. 3 shows a state where the light does not reach the light receiver. No. 3 sensor, as an infrared pulse D on which light-shielding data that has not been received is superimposed, a slave sensor No. Transmitting light toward 4

  When the infrared pulse from the previous sensor is cut off due to the shielding of the infrared light, the function to maintain the timing of the light transmission output until now works, and the self-oscillation of the self-transmitting device in the sensor causes the infrared sensor to the next sensor. A pulse D signal is output, sequentially transmitted by each sensor, returned to the master sensor, input to the control panel and processed, and predetermined control data is superimposed on the infrared pulse and transmitted.

As for the light transmission timing of each slave sensor, infrared pulses are sequentially transmitted to each sensor based on the top pulse of the infrared pulse of the master sensor.
JP-A-62-263489

  In the conventional system in which infrared pulses are sequentially transmitted through each sensor, as shown in FIG. 4, when the infrared pulse from the preceding sensor is shielded, the preceding sensor is detected by the self-oscillation of the self-transmitting device provided in the sensor. The infrared pulse D on which the light-shielding signal is superimposed is transmitted at a constant period even if the infrared pulse is not received. However, if the light-shielding state continues for a long time, each sensor is timed based on the time of the internal clock, and therefore, there is a gradual deviation (2) between the previous sensor cycle and the own sensor cycle. . In this light-shielded situation, even if a period shift occurs at the boundary of the sensor, the operation can be continued without any problems at this point. However, when the light shielding is restored, the infrared pulse B of the sensor in the previous stage is received and output after a lapse of a certain time, so that a new infrared pulse B is output during the output of the infrared pulse D and the error infrared pulse DB is set. Since all the subsequent sensors output and transmit the error infrared pulse DB sequentially, only one period becomes unstable. For this reason, for example, it is not uncommon for a similar return state to occur simultaneously in a plurality of sensors even when light is blocked for a long time due to fog, frost, or the like.

  In addition, when there is a building or the like adjacent between the sensors, infrared light received directly from the sensor in the previous stage and infrared light of other sensors reflected on the building may be received. Since it is not possible to determine whether or not the reference is determined for the top pulse, it may be out of synchronization and erroneously reported.

  Therefore, the present invention provides an infrared sensor that does not cause a synchronization shift even when infrared rays of the infrared sensor of the infrared monitoring system are shielded for a long time, and an infrared monitoring system using the same.

  The present invention is an opposed infrared sensor installed in a plurality of stages in an outdoor security area, which generates a reference time from a standard time acquired by a radio signal, and is generated by the reference time processing unit Using the reference time, the light transmission / reception timing processing unit that determines the light transmission timing at which the signal from the previous infrared sensor can be transmitted to the next infrared sensor, and the light reception timing from the light transmission / reception timing processing unit A light receiving processing unit having a signal processing unit that receives an infrared pulse and processes a signal from the preceding infrared sensor; an alarm processing unit that generates a light shielding signal when the infrared pulse is not received; and a light transmission timing And a light transmission processing unit for transmitting the signal processed by the light receiving processing unit as an infrared pulse.

  In the above configuration, the transmission / reception timing processing unit determines transmission / reception timing based on an address set so that the order in which infrared pulses are transmitted can be identified and the reference time, and a reference time generation unit The reference time can be generated from the standard time acquired from the GPS signal, and the reference time can be generated from the standard time acquired from the radio timepiece by the reference time generation unit.

  Furthermore, the present invention is composed of opposed infrared sensors installed in a plurality of stages in an outdoor warning area, and a control panel that monitors the warning area based on a light shielding signal detected by the infrared sensor. In the infrared system in which the infrared pulse is received and the infrared pulse is transmitted to the next-stage infrared sensor in sequence, and the light shielding signal of the infrared sensor at each stage is monitored by the control panel from the last-stage infrared sensor. Based on a reference time processing unit that generates a reference time from a standard time acquired by a wireless signal by a sensor, an address set so as to be able to identify the order in which infrared pulses are transmitted, and the reference time, the infrared pulse of the previous stage A light transmission / reception timing processing unit that determines a light transmission / reception timing at a timing at which a signal from the signal can be transmitted to the infrared sensor of the next stage; A signal processing unit that receives an infrared pulse at the light receiving timing from the scanning processing unit and processes a signal from the preceding infrared sensor; and an alarm processing unit that generates a light shielding signal when the infrared pulse is not received. And a light transmission processing unit for transmitting a signal processed by the light reception processing unit at the light transmission timing as an infrared pulse.

  Since the infrared sensor of the present invention obtains transmission / reception timing based on an accurate reference time generated from accurate time information of a radio signal such as GPS, the transmission / reception accuracy is improved. Since each sensor repeats light transmission and reception independently, there is no out-of-synchronization or false alarm due to the top pulse of the reflected infrared pulse, and there is no circuit part that matches the signal timing of the sensor in the previous stage. Becomes easier.

  In addition, the infrared monitoring system of the present invention provides each infrared sensor to obtain accurate time information from a radio signal such as a satellite so that each sensor independently transmits and receives light. There is no signal shift.

  FIG. 1A is a block diagram of a master sensor used in the system of the present invention, and FIG. 1B is a block diagram of the slave sensor. Each of the master sensor in FIG. 1A and each slave sensor in FIG. 1B includes a reference time processing unit 1, a light transmission / reception timing processing unit 2, and a light transmission / reception control unit 3.

  It is necessary to synchronize the master sensor and each slave sensor with high accuracy. In order to realize this, a GPS (Global Positioning System) can be used as shown in FIGS. The GPS 4 used here is a positioning system using standard time on an artificial satellite equipped with an atomic clock. This system provides a continuously accurate standard time.

  The GPS 4 receives a GPS signal from an artificial satellite input from the antenna 5.

  The standard time acquisition unit 6 acquires the standard time based on the GPS signal from the GPS 4 and sends the standard time to the reference time generation unit 7.

  The reference time generation unit 7 repeats frequency division from the standard time to perform high frequency processing, and generates an accurate reference time at a high frequency that can synchronize the sensors.

  Here, since the GPS signal from the GPS 4 has a low frequency (1 Hz pulse signal), it is necessary to set the high frequency (several KHz to several MHz) necessary for the sensor, but accurate time information can be obtained continuously at this high frequency. If there are other similar means, the GPS, the antenna, the standard time acquisition unit, and the reference time generation unit and the processing unit can be changed or omitted.

  For example, the standard time acquisition unit 6 may generate a reference time based on a signal received from a radio clock as means for obtaining an accurate time continuously.

  The reference time generated by the reference time generation unit 7 is output to the light transmission timing processing unit 8 and the light reception timing processing unit 9 of the light transmission / reception timing processing unit 2. An address corresponding to each sensor is input by the address input unit 10.

  The light transmission / reception timing processing unit 2 includes a light transmission timing processing unit 8, a light reception timing processing unit 9, and an address input unit 10, and is a high-frequency and accurate reference input from the reference time generation unit 7 of the reference time processing unit 1. Based on the time, the timing of light transmission and reception of the infrared pulse is determined, and the timing is output to the light transmission / reception controller 3.

  The address input unit 10 is composed of a dip switch, and inputs and sets an address, which is a code for individually identifying a master sensor and a slave sensor in the infrared monitoring system, according to a predetermined rule. Here, the predetermined rule is a rule in which the order in which the infrared pulse signal is transmitted between the sensors is set to be identifiable. Taking the infrared monitoring system shown in FIG. In the address setting for the infrared beam to which the infrared pulse signal is transmitted in the order of the slave sensor No2, the slave sensor No3, the slave sensor No4, and the slave sensor No5, the master sensor Nol is “00”, the slave sensor N02 is “01”, and the slave sensor No3 is “02”, slave sensor No4 is “03”, and slave sensor No5 is “04”. The reverse master sensor No. 1. Infrared beams to which infrared pulse signals are transmitted in the order of slave sensor No5, slave sensor No4, slave sensor No3, and slave sensor No2 can be handled because the order of transmission using the same address can be identified.

  In the present embodiment, in order to simplify the explanation, in the infrared monitoring system shown in FIG. The light transmission timing processing unit 8 and the light reception timing processing unit 9 will be described using a case where the slave sensor No. 2, the slave sensor No. 3, the slave sensor No. 4, and the slave sensor No. 5 are transmitted in this order.

  The light transmission timing processing unit 8 determines the timing for transmitting infrared light based on the reference time input from the reference time generation unit 7 and the address set in the address input unit 10.

  In other words, infrared pulses are transmitted every 20 milliseconds from the time multiplied by 20 milliseconds, for example, the address set in the address input unit 10 of each sensor. Here, 20 milliseconds is a time obtained by combining the time width of the infrared pulse and the interval time until the next infrared pulse is transmitted, and is a light transmission period in which the infrared pulse is transmitted. The light transmission cycle is determined in advance according to the installation environment and purpose of the infrared monitoring system. Note that a time of 1 second or more is not used because it does not have an important meaning for the transmission timing of the infrared pulse.

  Specifically, in the master sensor Nol, since the set address is “00”, light transmission is started from the time when the time in milliseconds becomes 000 milliseconds, 020 milliseconds, 040 milliseconds. , 060 milliseconds, 080 milliseconds, 100 milliseconds, 120 milliseconds,... 960 milliseconds, 980 milliseconds. In the slave sensor No. 2, the address is “01”, so the time in the millisecond unit is 01 × 2 milliseconds (several milliseconds are required for processing the signal from the previous stage. The transmission starts at 02 milliseconds calculated as (second), that is, 002 milliseconds, 022 milliseconds, 042 milliseconds, 062 milliseconds, 082 milliseconds, 102 milliseconds, 122 milliseconds. ... Output to the light transmission / reception control unit 3 so that light is transmitted at the timing of 962 milliseconds and 982 milliseconds. The other slave sensors No3 to No5 are also output to the light transmission / reception control unit 3 so as to transmit light at a timing delayed by 02 milliseconds.

  The light reception timing processing unit 9 determines the timing of receiving infrared rays based on the reference time input from the reference time generation unit 7 and the address set in the address input unit 10.

  That is, infrared pulses are received every 20 milliseconds from a time obtained by multiplying a value obtained by subtracting 1 from the address set in the address input unit 10 of each sensor, for example, 20 milliseconds.

  Here, 20 milliseconds is determined from the light transmission cycle for transmitting the infrared pulse signal, and is determined in advance in the infrared monitoring system. At this time, the time more than the unit of 1 second is not used.

  Specifically, in the slave sensor No. 2, since the set address is “01”, since the time in milliseconds is (01-1) × 20 milliseconds, the light is received from the time when it becomes 000 milliseconds. Start, receive light for 18 milliseconds. Thereafter, light reception is started at timings of 020 milliseconds, 040 milliseconds, 060 milliseconds, 080 milliseconds, 100 milliseconds, 120 milliseconds, 140 milliseconds,... 960 milliseconds, 980 milliseconds. In slave sensor No3, since the address is “02”, the time in milliseconds is calculated as (02-1) × 2 milliseconds (time for processing the signal from the previous stage), 02 milliseconds, That is, light reception is started at the time of 002 milliseconds, and light is received for 18 milliseconds. Thereafter, light is received at the timing of 022 milliseconds, 042 milliseconds, 062 milliseconds, 082 milliseconds, 102 milliseconds, 122 milliseconds,... 962 milliseconds, 982 milliseconds. The timings of the other slave sensors No. 4 to No. 5 are also output to the light transmission / reception control unit 3 so that light is transmitted at a timing delayed by 02 milliseconds.

  Accordingly, since the sensor itself is the light transmission timing after the light reception timing, the signal from the preceding sensor can be transmitted to the next sensor. As an infrared monitoring system, it is possible to accurately synchronize the timing at which the sensor on the light transmitting side transmits light and the timing at which the sensor on the light receiving side receives light.

  Here, regarding the light reception timing of the master sensor No. 1, the address of the last stage slave sensor (in FIG. 3, the address is “04” because the slave sensor No. 5 is the last stage), that is, “05” is the dip of the master sensor No. 1 The light receiving timing is determined in the same manner as other slave sensors based on the address.

  In addition, the transmission / reception timing processing unit 2 acquires an accurate reference time at a high frequency from accurate time information from the GPS system without wiring, and sets an address according to the order of each sensor to which the infrared pulse signal is transmitted. By doing so, the timing of light transmission and light reception can be accurately taken.

  The light transmission / reception control unit 3 transmits the infrared pulse to the light receiver 18 that is a photodiode that receives the infrared pulse, the light reception processing unit 14 that performs the light reception processing of the infrared pulse signal at the timing from the light reception timing processing unit 9. A light transmitter 17 which is a light emitting diode and a light transmission processing unit 11 which transmits an infrared pulse signal at the timing from the light transmission timing processing unit 8 are configured. The light reception processing unit 14 processes the sensor signal and control signal from the previous stage from the infrared pulse signal received by the light receiver 18 and outputs the processed signal to the light transmission processing unit 11. The light receiver 18 outputs the infrared pulse signal. When a light-blocking state that cannot be received is detected, the light-blocking data is generated and an alarm processing unit 15 that outputs the light-blocking data to the light transmission processing unit 11 is configured.

  The light transmission processing unit 11 superimposes the light shielding signal from the light receiving processing unit 14, the signal processing unit 13 that processes the received sensor signal and control signal from the previous stage, and the signal processed by the signal processing unit 13 on the infrared pulse. The signal generator 12 is configured to transmit an infrared pulse signal on which a signal is superimposed from the light transmitter 17 at the light transmission timing from the light transmission timing processing unit 8.

  Here, in the master sensor No. 1 shown in FIG. 1A, the light reception processing unit 14 outputs the received signal to the connected control panel 19. Further, the light transmission processing unit 11 processes a control signal from the control panel 19. In the slave sensor of FIG. 1B, signals are exchanged between the light reception processing unit 14 and the light transmission processing unit 11 as described above. Except for this point, the master sensor and the slave sensor perform the same processing.

  FIG. 2 is a time chart showing the transmission state of infrared pulses in the infrared system according to the present invention, and is an example in which the sensor of the present invention is applied to the sensor shown in FIG. In FIG. 2, A and B are infrared pulses on which pulses such as a top pulse indicating the start of an infrared pulse, sensor control data from the control panel, unit identification data, and sensor address data in an alarm section are superimposed, and D is a slave. Sensor No. 2 → Slave sensor no. Infrared pulses including a light-shielding signal, F and G, which detected the light-shielding in FIG. 2, No. 3 is an infrared pulse signal on which a signal such as battery low data 3 is superimposed.

  In FIG. 3, when the infrared pulse from the preceding sensor is shielded, each sensor transmits an infrared pulse D on which a shield signal between the sensors N02 and N03 is superimposed at a constant period. The infrared pulse D of each sensor is transmitted / received without causing any deviation in the cycle, with each sensor independently using the accurate reference time as the transmission / reception timing. At the same time, transmission of the infrared pulses F and G on which data such as the battery drops of N02 and N03 are superimposed is also performed without causing a shift in the cycle.

  When the light shielding is restored, the sensor N02 transmits the infrared pulse independently at a predetermined cycle without being affected by the timing of the infrared pulse of the preceding sensor N01. It works stably.

  By the infrared pulse light receiving process and the light transmitting process according to the present invention, each sensor uses an accurate reference time as a transmission / reception timing from a signal start position determined based on a standard time obtained from one common atomic clock. Thus, since the light transmission and reception are accurately repeated independently without being affected by the transmission / reception timing of the preceding sensor, the synchronization of the infrared pulses due to the long-time shielding of the infrared rays does not occur.

(A) is a block diagram of a master sensor used in the system of the present invention, and (b) is a block diagram of the slave sensor. It is a time chart which shows the transmission state of the infrared pulse of the infrared monitoring system by this invention. It is the schematic which shows an example of the sensor structure used for an infrared monitoring system. It is a time chart which shows the transmission state of the infrared pulse of the conventional infrared monitoring system.

Explanation of symbols

1: Reference time processing unit 2: Transmission / reception timing processing unit 3: Transmission / reception control unit 4: GPS
5: Antenna 6: Standard time acquisition unit 7: Reference time generation unit 8: Light transmission timing processing unit 9: Light reception timing processing unit 10: Address input unit 11: Light transmission processing unit 12: Signal generation unit
13: Signal processing unit 14: Light reception processing unit 15: Alarm processing unit 16: Signal processing unit 17: Light transmitter 18: Light receiver 19: Control panel

Claims (5)

It is an opposed infrared sensor installed in multiple stages in an outdoor security area,
A reference time processing unit for generating a reference time from a standard time acquired by a radio signal;
Using the reference time generated by the reference time processing unit, a light transmission / reception timing processing unit that determines a light transmission timing at which a signal from the previous infrared sensor can be transmitted to the next infrared sensor;
A signal processing unit that receives an infrared palace at a light receiving timing from the light transmission / reception timing processing unit and processes a signal from a previous infrared sensor, and an alarm process that generates a light shielding signal when the infrared pulse is not received A light receiving processing section having a portion,
An infrared sensor comprising: a light transmission processing unit configured to transmit a signal processed by the light reception processing unit at an optical transmission timing as an infrared pulse.   2. The infrared sensor according to claim 1, wherein the light transmission / reception timing processing unit determines the light transmission / reception timing based on an address set so that the order in which infrared pulses are transmitted can be identified and the reference time.   The infrared sensor according to claim 1, wherein the reference time processing unit generates a reference time from a standard time acquired from a GPS signal.   The infrared sensor according to claim 1, wherein the reference time processing unit generates the reference time from the standard time acquired from the radio timepiece. Consists of opposed infrared sensors installed in multiple stages in an outdoor security area and a control panel that monitors the security area based on the light shielding signal detected by the infrared sensor, and receives infrared pulses from the infrared sensor in the previous stage. In the infrared system that sequentially repeats sending infrared pulses to the infrared sensor of the next stage and monitors the light shielding signal of the infrared sensor of each stage from the infrared sensor of the last stage with the control panel,
The infrared sensor is
A reference time processing unit for generating a reference time from a standard time acquired by a radio signal;
A transmission / reception timing is determined at a timing at which a signal from the previous infrared pulse can be transmitted to the next infrared sensor based on the address set so that the order of transmission of the infrared pulse can be identified and the reference time. A light reception timing processing unit;
A signal processing unit that receives an infrared pulse at the light reception timing from the transmission / reception timing processing unit and processes a signal from the preceding infrared sensor, and an alarm that generates a light shielding signal when the infrared pulse is not received A light receiving processing unit having a processing unit;
An infrared monitoring system, comprising: a light transmission processing unit configured to transmit a signal processed by the light reception processing unit at the light transmission timing as an infrared pulse.

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